Fundamentals of crystallization: Kinetic effects on particle size distributions and morphology

Dirksen, James A.; Ring, Terry A.

doi:10.1016/0009-2509(91)80035-w

Cited by 481 publications

(369 citation statements)

References 66 publications

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“…In the case of diffusion controlled processes changes in the stirring rate, which can be conveniently expressed in terms of the specific power input, should influence the measured crystal growth rate [51]. Figure 5 shows for a molar inflow rate of 0.3 mol/h and a temperature of 80°C that the specific power input did not have any noticeable effect on the crystal growth rate within the range of investigated conditions.…”

Section: Influence Of Specific Power Input Of Stirringmentioning

confidence: 97%

The crystal growth kinetics of alpha calcium sulfate hemihydrate in concentrated CaCl2–HCl solutions

Feldmann

Demopoulos²

2012

Journal of Crystal Growth

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The crystal growth kinetics of calcium sulfate α-hemihydrate (α-HH) in nearly constant supersaturated HCl-CaCl 2 solutions were investigated. Two types of solutions were used, the first had a low HCl (1.4 mol/L) and high CaCl 2 (2.8 mol/L) concentration and the second had a high HCl (5.6 mol/L) and low CaCl 2 (0.7 mol/L) concentration. These conditions were chosen to represent the first and last stage of a newly developed stage-wise HCl regeneration process. The seeded growth experiments were carried out in a stirred, temperature controlled semi-batch reactor in which supersaturation was kept constant by simultaneous addition of CaCl 2 and Na 2 SO 4 solutions. The influence of the following parameters on α-HH crystal growth was studied: temperature (70-95°C), specific power input of stirring (0.02-1.29 W/kg) and equimolar inflow rate of CaCl 2 and Na 2 SO 4 (0-0.6 mol/h). The crystal growth rate was derived from particle size distribution measurements made with the laser light diffraction technique. It was found that the surface area normalized crystal growth rate increased linearly with the molar inflow rate up to 0.3 mol/h, at higher inflow rates no further increase of the growth rate was observed. Temperature and specific power input, within the investigated ranges, did not show a marked effect on the growth rate, attributable to a diffusion/adsorption controlled growth process. An interesting finding of the present research is the establishment of a positive relationship between the narrowing of the width of the particle size distribution with increasing crystal growth rate. The results show that the resulting particle size distribution is positively related to the reagent inflow rate, a finding that can be applied to the industrial design and scale-up of the α-HH crystallization/HCl regeneration process.

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Section: Influence Of Specific Power Input Of Stirringmentioning

confidence: 97%

The crystal growth kinetics of alpha calcium sulfate hemihydrate in concentrated CaCl2–HCl solutions

Feldmann

Demopoulos²

2012

Journal of Crystal Growth

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“…Compared to the crystal growth rate, the rate of nucleation is more dependent on supersaturation ratio, and the nucleation rate strongly influences the final crystal size distribution. [25][26] A higher degree of supersaturation ratio leads to a high nucleation rate and as a result, larger number nuclei are formed. Therefore, there is a much greater probability that form new nuclei rather than each nucleus could grow.…”

Section: Effects Of Experimental Parameters On the Particle Sizementioning

confidence: 99%

Surfactant Free Preparation of Celecoxib Microcrystals by a Controlled Precipitation Process

Mardani¹,

Maghsoodi²,

Hamishehkar³

2017

Pharm Sci

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“…According to the existing literature, 24,25 in the cases where a homogeneous nucleation process occurs, the characteristic pre-exponential factor of the nucleation rate B 0 and the solid-liquid interfacial energy ␥ can be Once the combustion process has been ignited, a hightemperature combustion front is formed, which propagates at a certain velocity along the pellet. To deal with a stationary combustion front that is not affected by ignition conditions, let us focus our attention on the time evolution of the reacting system at z = L/2 along the pellet axis.…”

Section: Numerical Solution and Model Outcomesmentioning

confidence: 99%

Combustion synthesis of metal carbides: Part II. Numerical simulation and comparison with experimental data

et al. 2005

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Based on the general theoretical model proposed in Part I of this work [J. Mater. Res. 20, 1257(2005], a series of numerical simulations related to the self-propagating high-temperature synthesis in the Ti-C system is presented. A detailed and quantitative description of the various physical and chemical processes that take place during combustion synthesis processes is provided in Part II of this work. In particular, the proposed mathematical description of the system has been discussed by highlighting the relation between system macroscopic behavior obtained experimentally with the modeled phenomena taking place at the microscopic scale. Model reliability is tested by comparison with suitable experimental data being nucleation parameters adopted for the fitting procedure. The complex picture emerging as a result of the model sophistication indicates that the rate of conversion is essentially determined by the rate of nucleation and growth. In addition, comparison between model results and experimental data seems to confirm the occurrence of heterogeneous nucleation in product crystallization.

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Fundamentals of crystallization: Kinetic effects on particle size distributions and morphology

Cited by 481 publications

References 66 publications

The crystal growth kinetics of alpha calcium sulfate hemihydrate in concentrated CaCl2–HCl solutions

The crystal growth kinetics of alpha calcium sulfate hemihydrate in concentrated CaCl2–HCl solutions

Surfactant Free Preparation of Celecoxib Microcrystals by a Controlled Precipitation Process

Combustion synthesis of metal carbides: Part II. Numerical simulation and comparison with experimental data

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